The Sungai Petang was declared a kelah sanctuary last month, sharing the protected status the Sungai Cacing, which also flows into the lake, has had since 1986.

The river is now under the watchful eye of the Fisheries Department, whose officers have so far had to turn away three groups of anglers unaware of the new ruling.

Sungai Petang has a 10km shallow stretch which is a spawning ground for kelah and lampam. Being easily accessible by boat, the stretch was popular with both recreational anglers and commercial fishermen.

"The State government is considering similar protection for three other rivers — Sungai Petuang, Sungai Tembat and Sungai Terengganu Mati.

"We are protecting a heritage, "Menteri Besar Datuk Seri Idris Jusoh told the New Straits Times. Some spawning grounds need to be protected and anglers can fish elsewhere in the lake."

Efforts are also being made to reduce the number of commercial freshwater fishermen.

"At the moment, we are not issuing new permits for commercial fishing in the lake," Idris said.